U.S. patent application number 11/253782 was filed with the patent office on 2007-04-19 for cutting tool assembly including diamond cutting tips at half-pitch spacing for land feature creation.
Invention is credited to Charles N. Devore, Jennifer L. Trice.
Application Number | 20070084316 11/253782 |
Document ID | / |
Family ID | 37946952 |
Filed Date | 2007-04-19 |
United States Patent
Application |
20070084316 |
Kind Code |
A1 |
Trice; Jennifer L. ; et
al. |
April 19, 2007 |
Cutting tool assembly including diamond cutting tips at half-pitch
spacing for land feature creation
Abstract
The invention is directed to a cutting tool assembly that
include multiple diamonds to define multiple cutting tips. A first
diamond is positioned in the cutting tool assembly to create a
first groove in a microreplication tool and a second diamond is
positioned in the cutting tool assembly to create a second groove
the microreplication tool, wherein the first and second grooves
define integer pitch spacing of a microreplication structure to be
created using the microreplication tool. In addition, a third
diamond is positioned in the cutting tool assembly between the
first and second diamonds to create a land feature in the
microreplication tool between the first and second grooves. The
invention can improve land feature creation by using a third
diamond tip, rather than leaving the land features untooled and
defined by the original untooled surface of micro-replication
tool.
Inventors: |
Trice; Jennifer L.; (Hugo,
MN) ; Devore; Charles N.; (Hugo, MN) |
Correspondence
Address: |
3M INNOVATIVE PROPERTIES COMPANY
PO BOX 33427
ST. PAUL
MN
55133-3427
US
|
Family ID: |
37946952 |
Appl. No.: |
11/253782 |
Filed: |
October 19, 2005 |
Current U.S.
Class: |
82/1.11 ;
407/119 |
Current CPC
Class: |
Y10T 407/23 20150115;
B23B 2220/12 20130101; B23C 3/32 20130101; B23C 5/08 20130101; B23B
29/26 20130101; B23B 2240/21 20130101; B23C 5/12 20130101; B23C
5/18 20130101; B23C 5/24 20130101; B23B 2226/31 20130101; Y10T
29/49995 20150115; B23B 27/06 20130101; Y10T 82/10 20150115; B23B
2226/36 20130101; B23C 2210/285 20130101; B23B 2240/08 20130101;
Y10T 407/27 20150115; B23B 27/20 20130101; B23B 2270/16
20130101 |
Class at
Publication: |
082/001.11 ;
407/119 |
International
Class: |
B23B 3/00 20060101
B23B003/00 |
Claims
1. A cutting tool assembly comprising: a mounting structure; a
first tool shank mounted in the mounting structure, the first tool
shank defining a first diamond tip that corresponds to a first
groove to be created in a work piece; a second tool shank mounted
in the mounting structure, the second tool shank defining a second
diamond tip that corresponds to a second groove to be created in
the work piece, wherein positions of the first and second diamond
tips define an integer number of pitches between grooves to be
created in the work piece; and a third tool shank mounted in the
mounting structure between the first and second tool shanks, the
third tool shank defining a third diamond tip to create a land
feature in the work piece between the first and second grooves.
2. The cutting tool assembly of claim 1, wherein a cutting location
of the third diamond tip is positioned at integer pitch plus
one-half pitch spacing relative to cutting locations of the first
and second diamond tips.
3. The cutting tool assembly of claim 2, wherein spacing between
the first and second tips is less than approximately 100 microns
and the cutting location the third diamond tip is positioned less
than 50 microns from the cutting locations the first and second
diamond tips.
4. The cutting tool assembly of claim 1, wherein the third diamond
tip defines a substantially flat cutting surface to define a flat
land feature in the work piece.
5. The cutting tool assembly of claim 4, further comprising a
fourth diamond tip that defines a substantially flat cutting
surface, wherein the third and fourth diamond tips define coplanar
lands in the work piece.
6. The cutting tool assembly of claim 1, wherein the third diamond
tip defines a non-flat cutting surface to define a non-flat land
feature in the work piece.
7. The cutting tool assembly of claim 1, wherein the third diamond
tip includes a flat portion and a sub-tip to define a land feature
in the work piece that includes a micro-groove sub-feature in the
land feature.
8. The cutting tool assembly of claim 1, wherein the cutting tool
assembly is a flycutting assembly configured to be rotated about an
axis perpendicular to a cutting direction of the diamond tips.
9. The cutting tool assembly of claim 1, wherein the work piece
comprises a microreplication tool used in creating optical film,
wherein the first and second diamond tips are shaped to create
grooves in the microreplication tool that correspond to features to
be created in the optical film and the third diamond tip is shaped
to create a flat land feature in the microreplication tool.
10. The cutting tool assembly of claim 1, wherein the work piece
comprises a microreplication tool used in creating optical film,
wherein the first and second diamond tips are shaped to create
grooves in the microreplication tool that correspond to features to
be created in the optical film and the third diamond tip is shaped
to create a non-flat land feature in the microreplication tool that
corresponds to a different feature to be created in the optical
film.
11. The cutting tool assembly of claim 1, wherein shapes of the
first and second diamond tips are substantially similar, and a
shape of the third diamond tip is substantially different than the
shapes of the first and second diamond tips.
12. The cutting tool assembly of claim 1, wherein the first and
second tool shanks are mounted to define the integer number of
pitches to within a tolerance of less than approximately 10
microns.
13. A diamond tooling machine used for creating grooves in a
microreplication tool comprising: a cutting tool assembly
comprising: a mounting structure; a first tool shank mounted in the
mounting structure, the first tool shank defining a first diamond
tip that corresponds to a first groove to be created in the
microreplication tool; a second tool shank mounted in the mounting
structure, the second tool shank defining a second diamond tip that
corresponds to a second groove to be created in the
microreplication tool, wherein positions of the first and second
diamond tips define an integer number of pitches of grooves to be
created in the microreplication tool; and a third tool shank
mounted in the mounting structure, the third tool shank defining a
third diamond tip to create a land feature in the microreplication
tool between the first and second grooves; and an apparatus that
receives the cutting tool assembly and controls positioning of the
cutting tool assembly relative to the microreplication tool.
14. The diamond tooling machine of claim 13, wherein the machine is
a fly-cutting machine that rotates the cutting tool assembly about
an axis, and wherein the apparatus includes a drive train coupling
the mounting structure to a motor.
15. The diamond tooling machine of claim 13, wherein the first and
second diamond tips are shaped to create grooves in the
microreplication tool that correspond to features to be created in
the optical film and the third diamond tip is shaped to create a
flat land feature in the microreplication tool.
16. The diamond tooling machine of claim 13, wherein the first and
second diamond tips are shaped to create grooves in the
microreplication tool that correspond to features to be created in
the optical film and the third diamond tip is shaped to create a
non-flat land feature in the microreplication tool that corresponds
to a different feature to be created in the optical film.
17. A method comprising: defining a pitch spacing for a
microreplication tool; creating a cutting tool assembly for
creation of the microreplication tool by: positioning first and
second tool shanks in a mounting structure such that a cutting
location of a first diamond tip associated with the first tool
shank is a defined distance from a cutting location of a second
diamond tip associated with the second tool shank, the defined
distance corresponding to an integer number of the pitch spacing,
wherein the defined distance is accurate to within a tolerance of
less than approximately 10 microns; and positioning a third tool
shank in a mounting structure such that a cutting location of a
third diamond tip associated with the third tool shank is between
the cutting locations of the first and second diamond tips to
create a land feature in the microreplication tool.
18. The method of claim 17, wherein positioning the third tool
shank further comprises positioning the third diamond tip at
integer pitch spacing plus one-half pitch spacing relative to both
the first and second diamond tips to within a tolerance of less
than approximately 10 microns.
19. The method of claim 17, further comprising: creating the
microreplication tool using the cutting tool assembly; and creating
microreplicated structures using the microreplication tool.
20. A cutting tool assembly comprising: a mounting structure; a
first tool shank mounted in the mounting structure, the first tool
shank defining a first diamond tip that corresponds to a groove to
be created in a work piece; and a second tool shank mounted in the
mounting structure, the second tool shank defining a second diamond
tip that corresponds to a land feature to be created in the work
piece, wherein the second diamond tip is spaced at integer pitch
spacing plus one-half pitch spacing relative to the first diamond
tip, wherein a pitch refers to a distance between adjacent grooves
created in the work piece.
21. The cutting tool assembly of claim 20, further comprising a
third tool shank mounted in the mounting structure, the third tool
shank defining a third diamond tip that corresponds to a second
groove to be created in a work piece, wherein the third diamond tip
is spaced at an integer pitch relative to the first diamond tip and
at an integer pitch plus one-half pitch relative to the second
diamond tip.
22. The cutting tool assembly of claim 20, further comprising a
third tool shank mounted in the mounting structure, the third tool
shank defining a third diamond tip that corresponds to a second
land to be created in a work piece, wherein the third diamond tip
is spaced at an integer pitch relative to the second diamond tip
and at an integer pitch plus one-half pitch relative to the first
diamond tip.
Description
FIELD
[0001] The invention relates to diamond machining of work pieces
such as microreplication tools that are used to fabricate
microreplicated structures.
BACKGROUND
[0002] Diamond machining techniques can be used to create a wide
variety of work pieces such as microreplication tools.
Microreplication tools are commonly used for extrusion processes,
injection molding processes, embossing processes, casting
processes, or the like, to create microreplicated structures. The
microreplicated structures may comprise optical films, abrasive
films, adhesive films, mechanical fasteners having self-mating
profiles, or any molded or extruded parts having microreplicated
features of relatively small dimensions, such as dimensions less
than approximately 1000 microns.
[0003] Microreplication tools include casting belts, casting
rollers, injection molds, extrusion or embossing tools, and the
like. Microreplication tools can be created by a diamond machining
process in which a cutting tool assembly is used to cut grooves or
other features into the microreplication tool. The process of
creating a microreplication tool using a cutting tool assembly can
be costly and time consuming.
SUMMARY
[0004] In general, the invention is directed to cutting tool
assemblies that include multiple diamonds to define multiple
cutting tips. The cutting tool assemblies having multiple diamonds
can be used in creating microreplication tools or other work
pieces. In accordance with the invention, at least two diamonds are
precisely positioned in the cutting tool assembly, one for cutting
a groove and one for cutting a land feature. In some cases, three
diamonds are precisely positioned in the cutting tool assembly,
e.g., with a land feature being cut between two groove
features.
[0005] For example, cutting tips of the diamonds can be used to
form grooves in a microreplication tool, and land features are
defined between the grooves in the microreplication tool. A first
diamond is positioned in the cutting tool assembly to create a
first groove in the microreplication tool and a second diamond is
positioned in the cutting tool assembly to create a second groove
the microreplication tool. The first and second grooves define
integer pitch spacing of a microreplication structure to be created
using the microreplication tool. In addition, a third diamond is
positioned in the cutting tool assembly between the first and
second diamonds to create a land feature in the microreplication
tool between the first and second grooves. In this sense, a cutting
tip of the third diamond is positioned at integer pitch spacing
plus one-half pitch spacing with respect to cutting tips of the
first and second diamonds.
[0006] The cutting tool assembly may include a mounting structure
and multiple tool shanks mounted in the mounting structure. Each of
the tool shanks can define a diamond tip used as a cutting tip of
the cutting tool assembly. At least two of the diamond cutting tips
of the tool shanks can be precisely formed and positioned to
correspond to grooves to be created in the microreplication tool.
At least one of the diamond cutting tips of the tool shanks may be
precisely formed and positioned to correspond to a land feature to
be created in the microreplication tool between the grooves.
[0007] Using microscopic alignment, the first and second tool
shanks can be precisely positioned in the mounting structure such
that cutting locations of the tips of the first and second diamonds
define one pitch spacing relative to one another. Accordingly, the
first and second diamond tips of the cutting tool assembly may
correspond to different grooves to be created in the
microreplication tool with integer pitch spacings defined by the
cutting locations of the diamond tips. The third tool shank can be
precisely positioned in the mounting structure using microscopic
alignment such that the cutting location of the tip of the third
diamond is between that of the first and second diamonds. The third
diamond is positioned to cut to a shallower depth than the first
and second diamonds so that a land feature can be created between
the grooves created by the first and second diamonds. The land
feature may define a planar land between the two grooves, or may
define a more complex land feature that has a shallower depth than
the grooves created by the first and second diamond tips.
[0008] In one embodiment, the invention provides a cutting tool
assembly comprising a mounting structure, a first tool shank
mounted in the mounting structure, the first tool shank defining a
first diamond tip that corresponds to a first groove to be created
in a work piece, and a second tool shank mounted in the mounting
structure, the second tool shank defining a second diamond tip that
corresponds to a second groove to be created in the work piece,
wherein positions of the first and second diamond tips define an
integer number of pitches between grooves to be created in the work
piece. In addition, the cutting tool assembly comprises a third
tool shank mounted in the mounting structure between the first and
second tool shanks, the third tool shank defining a third diamond
tip to create a land feature in the work piece between the first
and second grooves.
[0009] In another embodiment, the invention provides a diamond
tooling machine used for creating grooves in a microreplication
tool comprising a cutting tool assembly and an apparatus to receive
the cutting tool assembly and to control positioning of the cutting
tool assembly relative to the microreplication tool. The cutting
tool assembly includes a mounting structure, a first tool shank
mounted in the mounting structure, the first tool shank defining a
first diamond tip that corresponds to a first groove to be created
in the microreplication tool, a second tool shank mounted in the
mounting structure, the second tool shank defining a second diamond
tip that corresponds to a second groove to be created in the
microreplication tool, wherein positions of the first and second
diamond tips define an integer number of pitches of grooves to be
created in the microreplication tool, and a third tool shank
mounted in the mounting structure, the third tool shank defining a
third diamond tip to create a land feature in the microreplication
tool between the first and second grooves.
[0010] In another embodiment, the invention provides a cutting tool
assembly comprising a mounting structure, a first tool shank
mounted in the mounting structure, the first tool shank defining a
first diamond tip that corresponds to a first groove to be created
in a work piece, a second tool shank mounted in the mounting
structure, the second tool shank defining a second diamond tip that
corresponds to a second groove to be created in the work piece,
wherein positions of the first and second diamond tips define a
pitch between adjacent grooves of the work piece, a third tool
shank mounted in the mounting structure, the third tool shank
defining a third diamond tip to create a land feature in the work
piece between the first and second grooves, and a means for
securing the first, second and third tool shanks in the mounting
structure such that a cutting location of the first diamond tip
relative to the second diamond tip defines the pitch to within a
tolerance of less than approximately 10 microns, and a cutting
location of the third diamond tip defines a half pitch location
relative to both the first and second diamond tips to within a
tolerance of less than approximately 10 microns.
[0011] In another embodiment, the invention provides a method
comprising defining a pitch spacing for a microreplication tool and
creating a cutting tool assembly for creation of the
microreplication tool by positioning first and second tool shanks
in a mounting structure such that a cutting location of a first
diamond tip associated with the first tool shank is a defined
distance from a cutting location of a second diamond tip associated
with the second tool shank, the defined distance corresponding to
an integer number of the pitch spacing, wherein the defined
distance is accurate to within a tolerance of less than
approximately 10 microns, and positioning a third tool shank in a
mounting structure such that a cutting location of a third diamond
tip associated with the third tool shank is between the cutting
locations of the first and second diamond tips to create a land
feature in the microreplication tool.
[0012] In another embodiment, the invention comprises a cutting
tool assembly comprising a mounting structure, a first tool shank
mounted in the mounting structure, the first tool shank defining a
first diamond tip that corresponds to a groove to be created in a
work piece, and a second tool shank mounted in the mounting
structure, the second tool shank defining a second diamond tip that
corresponds to a land feature to be created in the work piece,
wherein the second diamond tip is spaced at integer pitch spacing
plus one-half pitch spacing relative to the first diamond tip,
wherein a pitch refers to a distance between adjacent grooves
created in the work piece.
[0013] By using multiple diamond cutting tips in the same cutting
tool assembly, the creation of the microreplication tool may be
improved or simplified. In particular, fewer cutting passes of the
cutting tool assembly may be needed to cut the grooves and land
features in the microreplication tool, which can reduce tooling
costs.
[0014] In addition, the invention can improve land feature creation
by using a third diamond tip, rather than leaving the land features
un-tooled and defined by the original un-tooled surface of
micro-replication tool. In this sense, the invention creates tooled
lands using a third diamond tip between two groove cutting tips,
wherein the third diamond tip cuts to a shallower depth than the
grove cutting tips. The third diamond tip defines a different
feature to be created in the microreplication tool relative to the
first and second diamond tips. Again, in one example, the feature
to be created by the third diamond tip comprises a planar land
feature. In this case, the invention can improve the planarity of
the microreplication tool that is created by the diamond cutting
tool. In another example, the feature to be created by the third
diamond tip comprises a land feature that includes a shallow
sub-groove that is shallower than the first and second grooves
created by the first and second diamonds. In this case, the land
feature between the first and second grooves can itself define an
optical feature to be created in a microreplication structure. The
width of the sub-groove formed within the land feature may be less
than the width of the land feature.
[0015] Additional details of these and other embodiments are set
forth in the accompanying drawings and the description below. Other
features, objects and advantages will become apparent from the
description and drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a conceptual top view of a multi-diamond cutting
tool assembly configured for fly-cutting.
[0017] FIG. 2 is a conceptual top view of a multi-diamond cutting
tool assembly configured for plunge cutting, thread cutting or
scribe cutting.
[0018] FIG. 3 is a conceptual top view of another embodiment of a
multi-diamond cutting tool assembly configured for fly-cutting.
[0019] FIG. 4 is a conceptual top view of another embodiment of a
multi-diamond cutting tool assembly configured for plunge cutting,
thread cutting or scribe cutting.
[0020] FIG. 5 is a conceptual top view of another embodiment of a
multi-diamond cutting tool assembly configured for fly-cutting.
[0021] FIG. 6 is a conceptual top view of another embodiment of a
multi-diamond cutting tool assembly configured for plunge cutting,
thread cutting or scribe cutting.
[0022] FIG. 7 is a conceptual perspective view of a multi-diamond
fly cutting tool assembly simultaneously cutting two grooves and a
land during the creation of a microreplication tool.
[0023] FIG. 8 is a conceptual perspective view of a multi-diamond
cutting tool assembly simultaneously cutting two grooves and a land
during the creation of a microreplication tool.
[0024] FIGS. 9A-9D are various cross-sectional top views
illustrating a multi-diamond cutting tool assembly cutting grooves
and flat land features into a work piece.
[0025] FIGS. 10A-10D are various cross-sectional top views
illustrating a multi-diamond cutting tool assembly cutting grooves
and lands with sub-features into a work piece.
[0026] FIG. 11 is a perspective view of an exemplary diamond that
can be used in a multi-diamond cutting tool assembly as one of the
groove cutting diamonds at pitch spacing.
[0027] FIG. 12 is a perspective view of an exemplary diamond that
can be used in a multi-diamond cutting tool assembly as a land
cutting diamond at half-pitch spacing.
[0028] FIG. 13 is a perspective view of an exemplary diamond that
can be used in a multi-diamond cutting tool assembly as a land
cutting diamond at half-pitch spacing to cut land features with
micro-grooves.
[0029] FIG. 14 is another perspective view of a fly-cutting tool
according to an embodiment of the invention.
[0030] FIG. 15 is a perspective view of a fly-cutting tool being
microscopically aligned.
[0031] FIG. 16 is a tip view of an alternative embodiment of a
fly-cutting tool according to the invention.
DETAILED DESCRIPTION
[0032] The invention is directed to cutting tool assemblies that
include multiple diamonds. The cutting tool assemblies having
multiple diamonds can be used in creating microreplication tools or
other work pieces. The microreplication tools, in turn, may be used
to create microreplicated structures, such as optical films,
abrasive films, adhesive films, mechanical fasteners having
self-mating profiles, or any molded or extruded parts having
microreplicated features of relatively small dimensions, such as
dimensions less than approximately 1000 microns.
[0033] In the following description, aspects of the invention are
described in the context of the creation of optical film. In that
case, the cutting tool assembly described herein is used to create
a microreplication tool, which is in turn used to create the
optical film. The described cutting tool assemblies, however, may
be used to create a variety of other work pieces. Accordingly, the
described cutting tool assemblies are not limited for use in
creating microreplication tools or optical film, and may find use
in a number of other tooling applications.
[0034] FIG. 1 is a top view of a cutting tool assembly 10 that
includes three tool shanks 11, 12 and 13 mounted in a mounting
structure 14. Cutting tool assembly 10 is configured for flycutting
in which assembly 10 is rotated about an axis 15. For example,
assembly 10 may be mountable to a drive shaft 16, which can be
driven by a motor of a tooling machine (not shown) to rotate
assembly 10. Mounting structure 14 may comprise a structure for
holding tool shanks 11, 12 and 13 that have diamond tips 17, 18 and
19. The shanks 11, 12 and 13 may be formed from a metallic or
composite material, and diamonds can be secured to shanks 11, 12
and 13 by a substantially permanent securing mechanism, such as a
solder, braze or adhesive. Alternatively, shanks may be permanently
secured to cartridges (not shown), which are in turn removably
secured to a fly wheel. FIG. 14 is a perspective view of a
fly-cutting tool 140 in which shanks 147 are permanently secured to
cartridges 146, which are in turn removably secured to a fly wheel
142. FIG. 14 is described in greater detail below.
[0035] Referring again to FIG. 1, at least three diamond cutting
surfaces, e.g., diamond tips 17, 18 and 19, are precisely
positioned in cutting tool assembly 10. Cutting tool assembly 10 is
then used to form grooves in a work piece to form a
microreplication tool and land features in the microreplication
tool between the grooves. More specifically, a first diamond is
positioned such that a first diamond tip 17 creates a first groove
in the microreplication tool and a second diamond is positioned
such that a second diamond tip 18 creates a second groove the
microreplication tool. The first and second grooves define integer
pitch spacing in the microreplication tool and correspond to a
pitch formed in optical film, which is subsequently created using
the microreplication tool. Although the first and second tips 17,
18 are illustrated as cutting grooves of similar depths, the
invention is not necessarily limited in this respect. For example,
the invention also contemplates a tool that includes a first groove
cutting tip at a first depth, a second groove cutting tip at a
second depth, and a land cutting tip between the first and second
groove cutting tips, the land cutting tip forming a land feature at
a third depth less than the first and second depths.
[0036] The one pitch spacing is labeled "P" in FIG. 1. However, "P"
may more generally refer to an integer number of pitches. If the
spacing is larger than one pitch, then subsequent cutting passes of
the tool may translate the cutting tips by one pitch in order to
allow for feature creation at the pitch. In the following
description, for simplicity, the invention is described in the
context of pitch spacing between the groove cutting diamond tips 17
and 18. However, it is understood that more generally, the groove
cutting diamond tips may be spaced at integer pitch spacing, with
the land cutting diamond tip 19 spaced at integer pitch spacing
plus one-half pitch spacing.
[0037] As shown in FIG. 1, a third diamond is positioned between
the first and second diamonds such that a third diamond tip 19
creates a land feature in the microreplication tool between the
first and second grooves. In this sense, a cutting tip of the third
diamond is positioned at one-half pitch spacing with respect to
cutting tips of the first and second diamonds. The one-half pitch
spacing is labeled "1/2 P" in FIG. 1. Again, however, third diamond
tip 19 may be, more generally, spaced at integer pitch spacing plus
one-half pitch spacing. The notation of pitch spacing and one-half
pitch spacing is used for simplicity in the following description,
although integer pitch spacing of the groove cutting tips and
integer pitch spacing plus one-half pitch spacing of the land
cutting tips is more generally contemplated by this disclosure.
[0038] Depending on the dimensions of the microreplication tool to
be created, the pitch spacing may be less than approximately 5000
microns, less than approximately 1000 microns, less than
approximately 500 microns, less than approximately 200 microns,
less than approximately 100 microns, less than approximately 50
microns, less than approximately 10 microns, less than
approximately 5 microns or less than approximately 1 micron.
[0039] Each of tool shanks 11, 12 and 13 defines at least one
diamond tip used as a cutting tip of cutting tool assembly 10,
although multi-tip diamonds could also be used in one or more of
shanks 11, 12 and 13. Again, at least two of the diamond cutting
tips (e.g., tips 17 and 18) are precisely formed and positioned to
correspond to grooves to be created in the microreplication tool,
and at least one of the diamond cutting tips (e.g., tip 19) is
precisely formed and positioned to correspond to a land feature to
be created in the microreplication tool between the grooves. Any
number of diamonds could be used, however, with grooves being
defined at pitch spacing (or integer pitch spacing) and lands at
one-half pitch spacing (or integer pitch spacing plus one-half
pitch spacing). When the microreplication tool created with cutting
tool assembly 10 is used to create the optical film, the grooves in
the microreplication tool may correspond to lands in the film and
the lands in the microreplication tool may correspond to grooves in
the film.
[0040] The third diamond tip 19 is positioned to cut to a shallower
depth than the first and second diamond tips 17, 18 so that a land
feature can be created between the grooves in the microreplication
tool. For example height H.sub.1 may be larger than height H.sub.2
such that the distance from diamond tips 17, 18 to axis 15 is
larger than the distance from diamond tip 19 to axis 15. Therefore,
the cutting performed by diamond tips 17, 18 delves further into
the microreplication tool than the cutting performed by diamond tip
19 such that diamond tips 17, 18 create grooves and diamond tip 19
creates a land feature.
[0041] The land feature may define a planar land between the two
grooves, or may define a more complex land feature that has a
shallower depth than the grooves created by the first and second
diamond tips. In either case, the tooling process can be improved,
particularly for land feature creation. In the example of FIG. 1,
the feature to be created by third diamond tip 19 may comprise a
planar land feature, in which case the invention can improve the
planarity of the microreplication tool that is created by cutting
tool assembly 10. In particular, the planarity of the tooled land
feature may be improved relative to a microreplication tool with an
untooled land feature that conforms to the original surface of a
work piece. In another example, (e.g., as shown and discussed below
with reference to FIGS. 5 and 6) the land feature to be created by
the third diamond (or other diamonds located at one-half pitch
spacing) may comprise a land feature that includes a shallow groove
relative to the first and second grooves created by the first and
second diamonds. In this case, the land feature between the first
and second grooves can itself define another optical feature to be
created in a microreplication structure via the microreplication
tool.
[0042] Cutting tool assembly 10 may be used to cut a plurality of
grooves and at least one land between the grooves on a
microreplication tool with a single cutting pass of cutting tool
assembly 10. Thus, the cutting time associated with the creation of
a microreplication tool can be reduced relative to using single tip
tools, or more complex patterns can be formed in a given period of
time. In this manner, the production cycle associated with the
ultimate creation of microreplication structures can be reduced,
and the production process may be simplified. Subsequent cutting
passes over the lands may also be avoided, thereby avoiding
conventional alignment problems associated with such subsequent
cutting passes.
[0043] The tips 17, 18 and 19 of the diamonds in tool shanks 11, 12
and 14 can be formed, for example, using lapping techniques,
grinding techniques, or focused ion beam milling processes. Various
shapes and sizes of the diamond tips are also described, which may
be useful in the creation of different microreplication tools.
Focused ion beam milling processes, in particular, may be used to
perfect the desired shapes of the diamond tips with extreme
accuracy.
[0044] The different tool shanks of the cutting tool assembly can
be mounted in a mounting structure using microscopic positioning
techniques. For example, the techniques may involve the use of a
tooling microscope with positioning controls. The microscope can be
used to identify and measure the position of the diamond tips
relative to one another so that the tool shanks can be properly
positioned within the mounting structure. Positioning feedback can
be provided to quantify the positioning of the diamond tips, e.g.,
in the form of a digital readout, analog readout, graphic display,
or the like. The feedback can be used to precisely position the
different tool shanks in the mounting structure. Once positioned,
the tool shanks can be secured in the mounting structure by any
suitable securing mechanism. In this manner, the tool shanks can be
positioned in the mounting structure such that a cutting location
of a first diamond tip is one pitch from a cutting location of a
second diamond tip, and the cutting location of a third diamond tip
is positioned at one-half pitch spacing relative to the first and
second cutting tips.
[0045] The use of a microscope and positioning feedback to
precisely position the multiple tool shanks within the mounting
structure can ensure placement of the diamond tips relative to one
another to tolerances required for effective tooling of
microreplication tools. In particular, positioning to locations
within tolerances of less than 10 microns, and more preferably less
than 1 micron can be achieved. Moreover, positioning of the diamond
tips to locations relative to one another within tolerances on the
order of 0.5 microns can be achieved using a tooling microscope
like that described herein. Such precision placement is desirable
for effective creation of microreplication tools that can be used
for creating a wide variety of microreplicated structures such as
microreplicated optical films, microreplicated mechanical
fasteners, microreplicated abrasive films, microreplicated adhesive
films, or the like.
[0046] In order to secure the diamonds in tool shanks 11, 12 and 13
and thereby define diamond tips 17, 18 and 19, a substantially
permanent securing mechanism can be used such as, brazing,
soldering, an adhesive such as an epoxy, or the like. Tool shanks
11, 12 and 13 with diamond tips 17, 18 and 19 can then be mounted
in mounting structure 14 via a temporary securing mechanism such as
one or more bolts, clamps or set screws (not shown). Alternatively
brazing, soldering, an adhesive such as an epoxy, or another more
permanent securing mechanism may be used to secure tool shanks 11,
12 and 13 in mounting structure 14. In any case, the use of a
tooling microscope with positioning controls and positioning
feedback can ensure that tool shanks 11, 12 and 13 are positioned
within mounting structure 14 such that diamond tips 17, 18 and 19
are positioned relative to one another with the precision required
for effective manufacture of microreplication tools. Mounting
structure 14 may have a shape that allows cutting tool assembly 10
to be inserted into a diamond tooling machine.
[0047] FIG. 2 is a conceptual top view of a multi-diamond cutting
tool assembly 20 configured for scribe cutting, plunge cutting or
thread cutting. As can be appreciated from FIG. 2, a cutting tool
assembly according to the invention may assume different
configurations, depending on whether it is designed for flycutting
or other types of cutting. Other non-fly cutting examples include
scribe cutting, plunge cutting or thread cutting. In plunge
cutting, a cutting tool assembly 20 is plunged into a moving work
piece at defined locations for intervals of time before moving to
other locations to cut various grooves or other features. Thread
cutting is similar to plunge cutting. However, in thread cutting,
cutting tool assembly 20 is displaced into a moving work piece for
longer periods of time to cut long threaded grooves. Scribe cutting
or ruling is similar to thread cutting, but in scribe cutting, the
cutting tool assembly 20 is displaced through a work piece very
slowly.
[0048] Like assembly 10 of FIG. 1, cutting tool assembly 20 of FIG.
2 includes multiple tool shanks 21, 22 and 23 secured within a
mounting structure 24. In order to secure the diamonds in tool
shanks 21, 22 and 23 and thereby define diamond tips 27, 28 and 29,
a substantially permanent securing mechanism can be used such as,
brazing, soldering, an adhesive such as an epoxy, or the like. The
tool shanks 21, 22 and 23 with diamond tips 27, 28 and 29, can then
be mounted in mounting structure 24 via a temporary securing
mechanism such as one or more bolts, clamps or set screws.
Alternatively, brazing, soldering, an adhesive such as an epoxy, or
another more permanent securing mechanism may be used to secure
tool shanks 21, 22 and 23 in mounting structure 24.
[0049] The use of a tooling microscope with positioning feedback
can ensure that diamond tips 27, 28 and 29 of tool shanks 21, 22
and 23 are positioned within mounting structure 24 with the
precision required for effective tooling of microreplication tools.
Mounting structure 24 may have a shape that allows cutting tool
assembly 20 to be inserted into a diamond tooling machine
configured for plunge cutting, thread cutting, scribing or
ruling.
[0050] Like in FIG. 1, the cutting tool assembly 20 of FIG. 2
includes two diamond tips 27 and 28 spaced one pitch (P) apart to
form grooves in a work piece. A third diamond dip 29 is spaced at
one-half pitch (1/2 P) relative to tips 27 and 28 to define a land
feature in the work piece. Again, The notation of pitch spacing and
one-half pitch spacing is used for simplicity in the embodiments
described herein. More generally, integer pitch spacing of the
groove cutting tips and integer pitch spacing plus one-half pitch
spacing of the land cutting tips is contemplated by this
disclosure. If the spacing of the tips is larger than one pitch
(i.e., spacing at integer pitches greater than 1), then subsequent
cutting passes of the tool creates the grooves at the desired
pitch. In the following description, every reference to pitch
spacing of diamond tips also contemplates integer pitch spacing of
such tips, and every reference to one-half pitch spacing of diamond
tips contemplates integer pitch spacing plus one-half pitch
spacing.
[0051] FIG. 3 is a conceptual top view of another embodiment of a
multi-diamond cutting tool assembly 30 configured for fly-cutting.
In this example, more tool shanks and more diamond tips are used.
Indeed, any number of tool shanks and diamond tips could be used.
In cutting tool assembly 30 of FIG.3, four tool shanks 31A, 31B,
31C and 31D (collectively shanks 31) that define diamond tips 32A,
32B, 32C and 32D (collectively diamond tips 32) for groove feature
creation. Diamond tips 32 are spaced one pitch (P) apart from one
another. Moreover, tips 32 are positioned at a height H.sub.1 to
define a groove depth in a microreplication tool.
[0052] Cutting tool assembly 30 also includes four additional tool
shanks 33A, 33B, 33C and 33D (collectively shanks 33) that define
diamond tips 34A, 34B, 34C and 34D (collectively diamond tips 34)
for land feature creation. Diamond tips 34 are also spaced one
pitch (P) apart from one another, but are spaced one-half pitch
relative to tips 32, which are used to create grooves. Tips 34 are
positioned at a height H.sub.2, which is less than height H.sub.1
of tips 32. In this manner, planarity of lands features can be
improved in the tooling of microreplication tools used to create
microreplicated structures.
[0053] FIG. 4 is a conceptual top view of another embodiment of a
multi-diamond cutting tool assembly 40 configured for scribe
cutting, plunge cutting or thread cutting. In FIG. 4, like the
example of FIG. 3, several tool shanks and several diamond tips are
used. Again, any number of tool shanks and diamond tips could be
used. In cutting tool assembly 40 of FIG. 4, four tool shanks 41A,
41B, 41C and 41D (collectively shanks 41) that define diamond tips
42A, 42B, 42C and 42D (collectively diamond tips 42) for groove
feature creation. Diamond tips 42 are spaced one pitch (P) apart
from one another. Moreover, tips 42 are positioned at a height to
define a groove depth in a microreplication tool.
[0054] Cutting tool assembly 40 also includes four additional tool
shanks 43A, 43B, 43C and 43D (collectively shanks 43), which are
positioned between shanks 41. Tool shanks 43 define diamond tips
44A, 44B, 44C and 44D (collectively diamond tips 44) for land
feature creation. Diamond tips 44 are also spaced one pitch (P)
apart from one another, but are spaced one-half pitch relative to
tips 42, which are used to create grooves. Tips 44 are positioned
at a height that is less than the height of tips 42. In this
manner, planarity of lands features can be improved in the tooling
of microreplication tools used to create microreplicated
structures.
[0055] FIG. 5 is a conceptual top view of another embodiment of a
multi-diamond cutting tool assembly 50 configured for fly-cutting.
In cutting tool assembly 50 of FIG. 5, four tool shanks 53A, 53B,
53C and 53D (collectively shanks 53) that define diamond tips 54A,
54B, 54C and 54D (collectively diamond tips 54) for groove feature
creation. Diamond tips 54 are spaced one pitch (P) apart from one
another. Moreover, tips 54 are positioned at a height HI to define
a groove depth in a microreplication tool.
[0056] Cutting tool assembly 50 also includes four additional tool
shanks 51A, 51B, 51C and 51D (collectively shanks 51) that define
diamond tips 52A, 52B, 52C and 52D (collectively diamond tips 52)
for land feature creation. Diamond tips 52 are also spaced one
pitch (P) apart from one another, but are spaced one-half pitch
relative to tips 54, which are used to create grooves. Tips 52 are
positioned at a height H.sub.2, which is less than height H.sub.1
of tips 54. In this manner, planarity of lands features can be
improved in the tooling of microreplication tools used to create
microreplicated structures. Moreover, in contrast to cutting tool
assembly 30 of FIG. 3, the diamond tips 52 used for land feature
creation include sub-tips, which define micro-groove sub-features
in a land feature. In this manner, more complex land features can
be created, e.g., to allow for the creation of more complex optical
film.
[0057] FIG. 6 is a conceptual top view of another embodiment of a
multi-diamond cutting tool assembly 60 configured for scribe
cutting, plunge cutting or thread cutting. In FIG. 6, like the
example of FIG. 4, several tool shanks and several diamond tips are
used. Again, any number of tool shanks and diamond tips could be
used. In cutting tool assembly 60 of FIG. 6, four tool shanks 61A,
61B, 61C and 61D (collectively shanks 61) that define diamond tips
62A, 62B, 62C and 62D (collectively diamond tips 62) for groove
feature creation. Diamond tips 62 are spaced one pitch (P) apart
from one another. Moreover, tips 62 are positioned at a height to
define a groove depth in a microreplication tool.
[0058] Cutting tool assembly 60 also includes four additional tool
shanks 63A, 63B, 63C and 63D (collectively shanks 63), which are
positioned between shanks 61. Tool shanks 63 define diamond tips
64A, 64B, 64C and 64D (collectively diamond tips 64) for land
feature creation. Diamond tips 64 are also spaced one pitch (P)
apart from one another, but are spaced one-half pitch relative to
tips 62, which are used to create grooves. Tips 64 are positioned
at a height that is less than the height of tips 62. In this
manner, planarity of lands features can be improved in the tooling
of microreplication tools used to create microreplicated
structures. Like the cutting tool assembly 50 of FIG. 5, cutting
tool assembly 60 of FIG. 6 utilizes land cutting diamond tips 64
that include sub-tips, which define micro-groove sub-features in a
land feature. In this manner, more complex land features can be
created, e.g., to allow for the creation of more complex optical
film.
[0059] FIGS. 7 and 8 are conceptual perspective views of systems 70
and 80 that use multi-diamond cutting tool assemblies 10 and 20 to
simultaneously cut two grooves during the creation of a
microreplication tool 72 (FIG. 7) or 82 (FIG. 8). In the examples
of FIGS. 7 and 8, the respective microreplication tool 72 or 82
comprises a casting roll, although other microreplication tools
such as casting belts, injection molds, extrusion or embossing
tools, or other work pieces could also be created using cutting
tool assembly 10 or cutting tool assembly 20. In some examples, the
work piece may be planar rather than a roll as shown in FIGS. 7 and
8. In FIG. 7, cutting tool assembly 10 may be rotated about an
axis. Cutting tool assembly 10 may also be moved relative to
microreplication tool 72 in lateral directions (as illustrated by
the arrows). At the same time, microreplication tool 72 may be
rotated about an axis. As cutting tool assembly 10 is rotated, two
diamond tips cut grooves into the microreplication tool 72 while a
third diamond tip cuts a land between the grooves. In this manner,
two grooves are formed in a single cutting pass of cutting tool
assembly 10, and a high quality land is formed between the grooves.
More complex land features may also be defined, e.g., by using a
more complex diamond tip shape for the tip that creates the land
features.
[0060] As shown in FIG. 8, cutting tool assembly 20 may be secured
in a diamond tooling machine 84 that positions the cutting tool
assembly 20 relative to microreplication tool 82, and moves the
cutting tool assembly 20, e.g., in lateral directions (as
illustrated by the arrows) relative to the microreplication tool
82. At the same time, microreplication tool 82 may be rotated about
an axis. Diamond tooling machine 84 may be configured to pass the
cutting tool assembly 20 into a rotating microreplication tool 82
via plunge or thread cutting techniques in order to cut grooves in
the microreplication tool 82. Alternatively, diamond tooling
machine 84 may be configured for scribing or ruling, in which
cutting tool assembly 20 is displaced through microreplication tool
82 very slowly. In any case, grooves and high quality lands can be
formed on microreplication tool 82. The formed grooves and lands
may define the ultimate form of microreplicated structures created
using the microreplication tool 72 (FIG. 7) or 82 (FIG. 8), for
example, during an extrusion process.
[0061] If desired, systems 70 and 80 may use a fast tool servo (not
shown). For example, referring to FIG. 8, a fast tool servo could
be employed between cutting tool assembly 20 and the tooling
machine 84 that receives cutting tool assembly 20. In this case,
the fast tool servo may vibrate the cutting tool assembly 20 for
creating of particular microstructures in microreplication tool
82.
[0062] Because the cutting tool assembly 10, 20 implements multiple
tool shanks, and thus multiple diamond cutting tips, fewer passes
of the cutting tool assembly are needed to cut the grooves on the
microreplication tool. This can reduce production costs and speed
the production cycle associated with creation of microreplication
tools. Moreover, systems 70 and 80 may improve land feature
creation by using a third diamond tip, rather than leaving the land
features un-tooled and defined by the original un-tooled surface of
microreplication tool 72 or 82. In the illustrated example of FIGS.
7 and 8, the feature to be created by the third diamond tip
comprises a planar land feature. In this case, the invention can
improve the planarity of microreplication tool 72, 82 that is
created by diamond cutting tool 10, 20. In other examples, however,
the feature to be created by the third diamond tip comprises a land
feature that includes a small and shallow groove (or other
sub-feature). In this case, the land feature between the first and
second grooves can itself define an optical feature to be created
in a microreplication structure. The width of the sub-feature
formed in the land feature may be less than the width of the land
feature.
[0063] Microreplication tools 72 and 82, or any work piece created
using the techniques described herein, may be formed of copper,
nickel, aluminum, plastic such as acrylic, or any material capable
of being machined. Generally, the machining techniques described
herein may be implemented by moving only the diamond cutting tips,
by moving only the work piece relative to the diamond cutting tips,
or by moving both the work piece and the diamond cutting tips.
[0064] The sizes of the diamond tips described herein may be
defined by a cutting height (H.sub.CUTTING), the cutting width
(W.sub.CUTTING), and pitch variables (P) and (1/2 P) defined above.
The cutting height (H.sub.CUTTING) defines the maximum depth that
the diamond can cut in a work piece, and may also be referred to as
the cutting depth. The cutting width (W.sub.CUTTING) may be defined
as the average cutting width, or the maximum cutting width of a
tip. Another quantity that can be used to define the size of the
cutting tips is referred to as the aspect ratio. The aspect ratio
is the ratio of height (H.sub.CUTTING) to width (W.sub.CUTTING).
Diamond tips created by focused ion beam milling processes can
achieve various heights, widths, pitches, and aspect ratios.
[0065] For example, the height (H.sub.CUTTING) and/or the width
(W.sub.CUTTING) can be formed to be less than approximately 500
microns, less than approximately 200 microns, less than
approximately 100 microns, less than approximately 50 microns, less
than approximately 10 microns, less than approximately 1.0 micron,
or less than approximately 0.1 micron. Additionally, the pitch
variable (P) may be defined to be less approximately 5000 microns,
less than approximately 1000 microns, less than approximately 500
microns, less than approximately 200 microns, less than
approximately 100 microns, less than approximately 50 microns, less
than approximately 10 microns, less than approximately 5 microns,
less than approximately 1.0 micron, and may approach 0.5 micron. In
some cases, by using offset positioning of tool shanks, the pitch
(P) may be less than the width of the tool shanks.
[0066] The aspect ratio (H.sub.CUTTING:W.sub.CUTTING) may be
defined to be greater than approximately 1:5, greater than
approximately 1:2, greater than approximately 1:1, greater than
approximately 2:1, or greater than approximately 5:1. Larger or
smaller aspect ratios may also be achieved using focused ion beam
milling. These different shapes and sizes may be advantageous for
various applications.
[0067] Focused ion beam milling refers to a process in which ions,
such as gallium ions, are accelerated toward the diamond in order
to mill away atoms of the diamond (sometimes referred to as
ablation). The acceleration of gallium ions may remove atoms from
the diamond on an atom by atom basis. Vapor enhancing techniques
using water vapors may also be used to improve the focused ion beam
milling process. One suitable focused ion beam milling machine is
the Micrion model 9500, commercially available from FEI Inc. of
Portland Oreg. In general, focused ion beam milling can be
performed to create precision tipped diamonds that correspond to
the features to be created. One exemplary provider of focused ion
beam milling services that may be used to create one or more ion
beam milled diamonds is Materials Analytical Services of Raleigh,
N.C.
[0068] Focused ion beam milling is generally very expensive.
Therefore, to reduce the costs associated with the creation of a
multi-tipped diamond, it is desirable to initially process the
diamond tip to be ion beam milled prior to submitting the diamond
tip to the focused ion beam milling process. For example, less
expensive techniques such as lapping or grinding may be used to
remove significant portions of the diamond tip. The focused ion
beam milling process may ensure that one or more of the dimensions
or features listed above can be achieved. Still, by initially
processing the diamond tip prior to focused ion beam milling, the
amount of focused ion beam milling time required to create the
final ion beam milled diamond tip can be reduced. Lapping refers to
a process of removing material from the diamond using a loose
abrasive, whereas grinding refers to a process in which material is
removed from the diamond using an abrasive that is fixed in a
medium or substrate.
[0069] FIGS. 9A-9D are cross-sectional top views illustrating a
cutting tool assembly 90 cutting grooves into a work piece 92. In
particular, FIG. 9A is a cross-sectional top view illustrating a
multi-diamond cutting tool assembly 90 cutting a first set of
grooves and lands into work piece 92. FIG. 9B is a cross-sectional
top views illustrating cutting tool assembly 90 cutting a second
set of grooves and lands into work piece 92, and FIG. 9C is a
cross-sectional top views illustrating cutting tool assembly 90
cutting a third set of grooves and lands into work piece 92. FIG.
9D is a top view illustrating the created work piece 92 after four
passes of cutting tool assembly 90. Work piece 92 may correspond to
a microreplication tool as outlined above, although the invention
is not necessarily limited in that respect. As shown, the land
features are flat and coplanar as defined by the land cutting
diamond tips spaced at one-half pitch spacing relative to the
groove cutting diamond tips.
[0070] FIGS. 10A-10D are cross-sectional top views illustrating a
cutting tool assembly 100 cutting grooves into a work piece 102. In
particular, FIG. 10A is a cross-sectional top view illustrating a
multi-diamond cutting tool assembly 100 cutting a first set of
grooves and lands into work piece 102. FIG. 10B is a
cross-sectional top views illustrating cutting tool assembly 100
cutting a second set of grooves and lands into work piece 102, and
FIG. 10C is a cross-sectional top views illustrating cutting tool
assembly 100 cutting a third set of grooves and lands into work
piece 102. FIG. 10D is a top view illustrating the created work
piece 102 after four passes of cutting tool assembly 100. Like in
FIG. 9D, the created work piece 102 of FIG. 10D may correspond to a
microreplication tool as outlined above, although the invention is
not necessarily limited in that respect. As shown, the land
features 106 are flat and coplanar but include sub-features 107,
which in this example take the form of micro-grooves that are
shallower than groove features 105.
[0071] FIG. 11 is a perspective view of a diamond 110 that can be
secured into a tool shank and then used in a cutting tool assembly.
Diamond 110 may correspond to any of diamond tips 17, 18, 27 or 28
described above. As shown in FIG. 11, diamond 110 may define a
cutting tip 112 defined by at least three surfaces (S1-S3).
Surfaces S1, S2 and S3 may be created by grinding or lapping
techniques, and may be perfected by focused ion beam milling
techniques.
[0072] FIG. 12 is a perspective view of a diamond 120 that can be
secured into a tool shank and then used in a cutting tool assembly.
Diamond 120 may correspond to either of diamond tips 19 or 29
described above. As shown in FIG. 12, diamond 120 may define a flat
cutting tip 122 which can create flat land features.
[0073] FIG. 13 is a perspective view of a diamond 130 that can be
secured into a tool shank and then used in a cutting tool assembly.
As shown in FIG. 13, diamond 130 may define a flat cutting tip 132
that includes a small sub-tip 134 to define micro-groove
sub-features in a land feature. Sub-tip 134 may have a shape that
is like that of diamond 110 in FIG. 11, but is a smaller protruding
feature a larger diamond 130. Diamond 130 with flat cutting tip 132
and sub-tip 134 may be used to define land features that include
micro-grooves. Again, focused ion beam milling techniques may be
used to define the diamond shapes described herein.
[0074] FIG. 14 is another perspective view of a fly-cutting tool
according to an embodiment of the invention. In tool 140 FIG. 14,
fly wheel 142 rotates on a drive shaft of fly cutting machine 144.
Cartridges 146A-146G (collectively cartridges 146) are removably
secured into fly wheel 142. Fly wheel 142 is one example of a
mounting structure that can receive tool shanks 147A-147G, e.g.,
secured into the removable cartridges 146. Each of cartridges 146
includes at least one of tool shanks 147 that includes at least one
diamond tip for cutting features into a work piece. In this
example, cartridges 146A, 146C and 146E define groove-cutting tips
that are spaced laterally apart with respect to a rotational axis
of fly wheel. Similarly, cartridges 146B, 146D and 146F define
land-cutting tips that are spaced laterally apart with respect to a
rotational axis of fly wheel.
[0075] The groove-cutting tips in cartridges 146A, 146C and 146E
may be incrementally spaced to define three pitch-spaced grooves in
a work piece, while the land-cutting tips in cartridges 146B, 146D
and 146F are at one-half pitch spacing to define three land-spaced
grooves in a work piece. Although illustrated as being in an
alternating configuration, the groove-cutting tips and land-cutting
tips may be positioned in other cartridges of flywheel. Also,
although land-cutting tips in cartridges 146B, 146D and 146F are
illustrated as being flat tips, these flat tips may also include a
small sub-tip to define micro-groove sub-features in a land
feature, e.g., as shown in diamond 130 of FIG. 13.
[0076] FIG. 15 is a perspective view of a fly-cutting tool being
microscopically aligned. In particular, in order to obtain diamond
tip alignment to within the tolerances described herein, a
microscope 152 may be used. While under microscope 152 the
positions of the diamond tips of tool 150 can be adjusted to define
precise pitch and one-half pitch spacing of the various cutting
tips. Goniometer adjustment can be performed to ensure proper
angular positioning of the fly wheel 156. In addition, an X-Y
flexure device 158 may be used to ensure proper spatial positioning
of the cutting tips within the various cartridges secured into fly
wheel 156. Microscope 152 is used to ensure both angular and planar
positioning of the cutting tips to within the tolerances described
herein.
[0077] The center of rotation of the fly-cutting tool can be
maintained by a locating sphere attached to the fly-cutting tool
and receiver bores mounted in spindles of the fly-cutting tool. The
receiver bores can be aligned to the axis of rotation of the
spindles. Fly-cutting tool pilot balls may also be located along
with the mating face of the fly-cutting tool to define the center
of rotation of the fly-cutting tool. A fine motion rotation
adjustment can be used to bring the fly-cutting tool into focus
without moving the focus adjustment on the microscope stage. This
removes any precision alignment and motion requirements from the
focus stage of the microscope since that degree of freedom can be
locked. Goniometer adjustment can be performed to ensure proper
angular positioning of the fly wheel 156. The tip of the
fly-cutting tool can be placed at the center of rotation to
eliminate the translations that would be present otherwise. A
precision X-Y flexure device 158 may be used to translate the
cutting tools in two degrees of freedom relative to the rotor body
without backlash.
[0078] For some cutting tools, the entire mastering process can be
achieved without moving the microscope stage. When all the tool
shanks are mounted in position, the microscope stage can be used to
move the microscope objective out of the way and back into position
so that the completed cutter can be fully inspected. When the
cutting tips have been adjusted to the desired location and
rotation, that position is locked in place by adhesive. A safety
pin may be supplied in case the adhesive fails during subsequent
cutting operations. If subsequent inspection finds one or more tips
are not properly located, the out of specification cartridge and
tool can be remove and replaced with a blank cartridge without
disturbing the other tools.
[0079] Tapped holes may be provided to attach balance weights. In
addition, tapped radial holes may be used to provide for fine
balance adjustment set screws. Dummy cartridges can be used as
counter weights if less than a full complement of six tools is
loaded. The dummy cartridges may contain coarse balance adjustment
screws. Due to the disc like design, dynamic balancing may not be
required. A simple static balance between straightedges provides
excellent balance results. A through hole can be used as a balance
shaft.
[0080] FIG. 16 is a tip view of an alternative embodiment of a
fly-cutting tool 160 according to the invention. Like cutting tool
assembly 10 of FIG. 1, cutting tool assembly 160 of FIG. 16
includes at least three diamond cutting surfaces, e.g., diamond
tips 167, 168 and 169. Moreover, diamond tips 167 and 168 may be
spaced to define one pitch, while diamond tip 169 is positioned at
one-half pitch spacing with respect to diamond tips 167 and
168.
[0081] Unlike tool 10 of FIG. 1, however, a fly cutting tool 160 is
configured such that a cutting location of diamond tips 167, 168
and 169 is parallel to a rotation axis 165 of fly cutting tool 160.
In this case, diamond tips 167, 168 and 169 may form circular
groove and land features in a work piece.
[0082] A number of embodiments have been described. In particular,
a cutting tool assembly has been described that defines least two
diamond cutting tips that correspond to grooves to be created in
the microreplication tool and at least one diamond cutting tips
that corresponds to a land feature to be created in the
microreplication tool between the grooves. The invention is
particularly useful in improving land feature creation by using a
third diamond tip, rather than leaving the land features un-tooled
and defined by the original un-tooled surface of micro-replication
tool.
[0083] Nevertheless, various modifications may be made to the
structure and techniques described herein without departing from
the spirit and scope of the invention. For example, the cutting
tool assembly may be used to cut grooves and lands into other types
of work pieces, e.g., work pieces other than microreplication
tools. Also, in other uses, two or more groove cutting diamonds may
be secured in a tool shank as described herein, but secured with
the cutting tips at different depths. In that case, the groove
cutting diamonds may be spaced at integer pitch spacing and can be
used to cut the same groove, e.g., with deeper and deeper cuts
being made by different diamonds during subsequent passes of the
tool. In this case, the land cutting diamond may still be used to
create flat coplanar lands or lands with sub-features as described
herein.
[0084] In still other cases, two land cutting diamonds may be used
with one groove cutting diamond in a cutting tool. Also, for even
more complex feature formation, the land cutting diamonds may be
non-planar such that lands of different depths are created by a
single cutting pass of the tool. Accordingly, other implementations
and embodiments are within the scope of the following claims.
* * * * *